Let's not forget that in the early 80's, more than 8 bits per character was something that almost never happened.
It was a real PITA because it was underbar (_, shift-dash) on the keyboard iirc.
Any assignment made me want to drink, thus the character name.
We can revisit the character sets now that Unicode is ubiquitous. As for typing non-ASCII characters, that has been daily practices for decades _outside_ of north America.
Tildes in Spanish are just used to mark the stressed syllabe when it's outside the stressing rules, and the diaeresis it's to make the 'u' non silent in gue/gui/que/qui. So if we read "funcion" without being written "función", don't worry, we aren't writting a literary test, it's code.
I'd hate to debug code written in Chinese instead of English. And Golang allows that I think, and lots of languages too.